Clamp



July 20,1948. H. D. GuRs Y emu? r2 Sheets-Sheet 1 Filed July 12, 1946 [N V EN TOR. Hen/'70. 6ursfiy July 20, 1948. H. D. GURSKY CLAMP 2 Shets-Sheet 2 Filed July 12, 1946 Patented July 20, 1948 CLAW Henry D. Gursky, Gloversvilic, N. Y., assignor to Curtin-Hebert Company,

1110., Gloversville,

N. Y., acorporation of New York Application July 12, 1946, Serial No. 683,286 8 Claims. (Cl. 51-194) This invention relates to a clamp. The clamp members may be shaped to conform to the-surface to which they are to be applied. One specific use for the clamp is to detachably secure a sheet of sandpaper wrapped around aqcylinder which may be rotatably mounted to provide a wide gauge buffing or abrading surface. For such an operation clamp members are required adapted to overcome large frictional forces which tend to displace the sheet, and to quicklyv destroy it if it becomes loose or displaced. It is also important that the clamp can be quickly positioned and tightened and released since the sheets have to be frequently replaced.

Accordingly it is an object of thisinvention to provide a simple, practical and efficient demountable clamp. y

Another object of the invention is to provide dependable clamp means which can be speedily tightened and released.

Another object of the invention is to provide clamp means adapted to cooperate with an annular flange protruding from the end of arcylinder to fasten a replaceable flexible member on and around the surface of the cylinder.;

Another object of the invention is to provide clamp means adapted to fit over a curved surface around a section of acircle;

Other objects of the inventionwill be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts, and. in the several steps and relation and order of each of said steps to one or more of the others thereof, all as will be pointed out in the following description, and the scope of the application of which, will be indicated in the following claims. v p

The invention will best be understood if the following description is read in connection with the drawings, in which,y

Figure 1 is anelevational view, partly in section, taken on the line l--,| of Figure 4, showing a clamp being locked in position over. the flange 20";

Figure 2 is a view similar to Figure 1, taken on the line 2-2 of Figure 4, showing the clamp being released but before screws [6 have been loosened; i

Figure 3 is a front view of the clamp taken on the line 33 of Figure 1; a

Figure 4 is an end view, looking in the direction indicated by the arrows 4-4 in Figure 2;

Figure 5 is a front view of a number of clamps applied over the end flange of a cylindrical mem- 2 her to secure a flexible strip on the surface of the member; r

Figure 6 is an elevational view looking in the direction indicated by the arrows 65 in Figure 5;

Figure 7 is a rear elevational view of one Wedging or locking element of the clamp;

Figure 8 is a side view of the member shown in Figure 'I;

Figure 9 is a rear elevation of a second wedge or looking member utilized in the clamp;

Figure 10 is a sectional side view of the element shown in Figure 9;

Figure 11 is an elevation of a double ended differentially threaded screw used in connection with the element shown in Figures 9 and 10 and Figure 12 is an end view of the device shown in Figure 11 looking in the direction of the arrows l2-l2. p In the embodiment of the invention illustrated herein a clamp body member In is shown comprising, a central or intermediate portion I [interconnecting, a base portion l2 projecting at a right angle to the portion H from one end of member II, and a portion or jaw l3 projecting at a right angle from the other end of member H and parallelwithportionl2.

Cooperating with the clamp body III are the wedge members l4 and [5 respectively eachof which has an inclined face, the inclined face of one wedge being complementary to the inclined face of the other member. As illustratedherein the wedges are mounted on the clamp body in with the inclined face M of member i4 arranged in abutting relation to the inclined face (5 of member I5. p r 7 Each member [4 is provided with two bores l4! extending into said member from the rear and internally threaded to receive the threaded ends of shoulder screws l6 respectively. The central portion H of the clamp ID has the oval shaped slots l1 adapted to receive the screws l6 respectively and to give them somefreedom of movement toward and away from clamp arm [3 to facilitate the positioning and the locking and the unlocking of the members Hi. The enlarged heads of screws IE are received within the outer ends of slots I! but bridge the shoulders l'l formed in the side walls of the slots.

Member I 5, which, as illustrated, may be shorter from front to rear than member 14, has a bore l5 extending through it from front to rear, internally screw threaded to receive therein the forward portion l8 of a screw member 18, hereinafter referred to as a differential screw, which also has a portion 18 of increaseddiam-,

eter adapted to be received within a bore [9 in said clamp portion H, bore l9 being located below, and preferably intermediate, the slots H.

The screw member [8 is difierentially threaded. By this is meant that the portion w is threaded with less screw threads than the portion l8. For example the portion l8 may be given eighteen right hand screw threads, while the portion 18 may be given twenty left hand screw threads. As a result the same rotative movement, by which the portion 18 of differential screw I3 is engaged in the threaded bore IQ of clamp por= tion II, and moved inwardly, will serve to en- When it is desired to unlock the clamp, as for example, for substituting a new sheet of sandpaper for a used sheet, it is only necessary to rotate differential screw it in a direction to cause wedge [5 to travel outwardly on screw portion I8 thus relieving the pressure exerted on the wedge member I4 and allowing member l4 and its screws 46 to move away from the lower face of the flange 20 of cylinder 20. The extent of movement of screws [6 within slots IT is sufiicient to permit a new sheet of sandpaper to be substituted for a used sheet without disengaging gage member l5 on said portion 18, and cause member to travel down the full length bflthe portion [8 until the wedge member M has been elevated sufiiciently so that the members to be secured together, which in the application of the clamp illustrated herein are the annular'flange Ml and the strip of sandpaper 2i, have been firmly engaged between member l4 and jaw 13. Because of the diiierence in the number of the screw threads on the portions I8 and l8 respectively the wedge I5 will travel inwardly or 'outwardl-y on screw portion l8 faster than portion l8 will travel inwardly or outwardly of bore l9. Thus member [5 may be completely seated to elevate member 14 to the limit of its upward, or radially outward, movement controlled by the length of slots 11-, and provide a lock for member H, and the movement of member it for locking or unlocking may be speedily-accomplished. 7

Screw It may desirably be formed with alsocket head as shown, designed to receive a tool by which force sufilcient to readily turn the screw may be applied. I

In assembling each clamp ill the screws it are inserted into the slots l1 respectivelyfand their threaded ends are engaged in the bores M re spectively of the wedge member 14. Each screw 16 is tight against its shoulder but is movable lengthwise of the slot i'l through whi ch'it ex tends due to the fact that the shoulder section of the screw is made a little longer than the thickness of the cross section of the intermediate clamp portion ll'through whichthe screw extends. 'Thus each screw i6 and the wedge member I4 into which it mates, are movable to the extent permitted by the length oi the slot 11 through which the screw extends. Next'the differential screw 18 is insertedin the threaded bore I9 of clamp portion H 'with its end W projecting inwardly in a position to receive thereon the member I5. Screw 1-8 is now turned causing wedge member [5 to be drawn inwardiy'on 1Y8 until the clamp-is tightened. Since its 'face' l5 is toward the Tate t4 otwedge member M, as member 15 move inwardly it will move the member l4 toward jaw 13, within'therange of movement of screws 16 permitted by }the length of the slots 11 in clamp portion 'H Thus member i i serves as a clamp armor jaw engaging the under or near surface of flange 203.01 cylinder 20, in coaction with 'elampportion 13 which engages the other surface of flange 2B or any member intera posed be'tween itand the surface of cylinder 29.

In the embodiment of the invention illustrated in the drawings the clamp portion or jaw 'l3.1engages and securely holds'on the periphery of cylinder a sheet of sandpaper 2i whichis wound around the surface oi the drum. Ehe member 1-5 serves to hold member -14 against the under surface of cylinder flange "2 6 thus'pulling the clamp portion or jaw 1'3 down to engage the sh'eet'of sandpaper.

member M from the screws I8.

It will thus be seen that there has been provided by this invention an apparatus in which the various obj ects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As various possible embodiment's might be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invem tion, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings-is to be interpreted as illustrative and not in a limiting sense.

What I claim is: I

1. A clamp comprising a U-shaped member, a wedge member movably supported within the arms of said U-shaped member, and a second' wedge member positioned within the arms of said U-shaped member in abutting relation to said first wedge member, and means for moving one wedge member relative to the other to control the position of said f rst wedge member,

2. A clamp comprising an angle member having a first arm a second arm substantially'at right angles to-said first arm, a first member having opposite faces angularl'y disposed with respect to one another, means for supporting "said member from said second arm for movement toward or away from said first arm, a second memher having pposite faces angularly disposed with respect to one another, and means for supporting said second member from said second arm and for moving it toward "or away nemsaid second arm to cause an inclined face of said mond member to engage an oppositely inclined face of said first member to move said first member toward said first arm and to hold said first 'member in its after being moved. :3. A clamp adapted to .fit over an annular fiangeon the end of a cylindrical member to-lock a flexible member on the surfaceoi said cylindrical member, comprising an angle member having a jaw adapted to fit over a portion of the annular flange of said cylindrical member, and a support portion angularlyreiated to said jaw portion and adapted to extend substantially parailel' to end surface of said cylindrical member, a second jaw member detachably mounted on said support portion having an upper "surface adapted to fit up against the under sideo'f the saidannular flang'eoi said cylindrical member and having an under surface inclined from said support portion toward said annular flange, and for positioning and locking said second jaw member again-st sa'id anniflar flange com-' prising a wedge member having an inclined face; and'rneans forsupporting saidwedge member for movement toward or away fi'o'm said support portion with its inclined face opposed to the .in-. clined face of saidsecond -jaw member, and 'posi tioned toprog-ressiveiy engage and elevate 's-aid second saw member.

4. A clamp comprising a support portion, and upper and lower jaw members supported from said support portion in parallel relation, one of said jaw members being movable toward and away from the other, a wedge member, and means supported from said support portion for moving said wedge member to control the position of said movable jaw member relative to the other of said jaw members and to serve as a releasable lock for said movable jaw member.

5. A clamp comprising a support portion, and a fixed jaw member and a movable jaw member supported from said support portion substantially in parallel relation, a wedge member, having a grooved bore, and said support portion having a grooved bore of greater diameter than the said bor of said wedge member, and a screw having differentially threaded portions including a head portion threaded to engage in the said bore of said support portion, and a portion of less diameter than said head portion adapted to engage in the said bore in said wedge member, the grooves of said bores being opposite hand, and the two threaded portions of said screw being opposite hand whereby the same rotation of the screw for seating its head portion in said support portion will draw said wedge onto and along the portion of less diameter of said screw and progressively into engagement with said movable jaw member to move it toward said fixed jaw member.

6. In a clamp assembly comprising a support member having a grooved bore, a pair of jaws, one of which is fixedly related and the other movably related to said support member, a Wedge having a grooved bore, and a screw having two sets of oppositely handed threads, one set of said threads being adapted to engage the grooves within the bore of said support member, and the other set of said threads being adapted to engage the grooves of the bore of said wedge, rotation of said screw serving both to advance the screw into said support member and simultaneously to draw said wedge onto said screw toward said support member into contact with 6, said movable jaw member to control the position of said movable jaw member.

7. In a clamp assembly comprising a support member having a grooved bore, a pair of jaws, one of which is fixedly related and the other movably related to said support member, a wedge having a grooved bore, and a screw oppositely threaded on opposite ends, the threads on the head end of said screw being adapted to engage the grooves within the bore in said support member, and the threads on the forward end of said screw being adapted to engage the grooves of the bore of said wedge, and the threads on the forward end of said screw being greater in number than the threads on the head end of said screw.

8. A clamp, for holding paper on the surface of an abrasive drum having laterally extending annular flanges, comprising, a jaw adapted to fit over a portion of the exterior surface of the drum, support means for the jaw extending radially of the drum, a first wedge member having an outer surface adapted to fit against the inner surface of said annular flange, said Wedge member having an inner inclined surface, a second wedge member having an outer face inclined oppositely to the inner face of said first member, means for mounting said first and second members with their inclined faces in contact, and means for moving said members relatively to cause said first member to grip the inner surface of said annular flange.

HENRY D. GURSKY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,010,557 Nenninger et al Aug. 6, 1935 FOREIGN PATENTS Number Country Date 493,985 Great Britain Oct. 18, 1938 

